Add empty-seq? function and update nodes-from-opt to handle empty sequences (#13)

2 files changed, 22 insertions, 0 deletions

diff --git a/src/dompa/nodes.cljc b/src/dompa/nodes.cljc
index d2f8e4b..eef65d3 100644
--- a/src/dompa/nodes.cljc
+++ b/src/dompa/nodes.cljc
@@ -142,11 +142,19 @@
   (and (sequential? coll)
        (> (count coll) 1)))
 
+(defn- empty-seq?
+  [coll]
+  (and (sequential? coll)
+       (empty? coll)))
+
 (defn- nodes-from-opt
   [opt]
   (cond (map? opt)
         opt
 
+        (empty-seq? opt)
+        nil
+
         (list-of-many? opt)
         {:node/name :<>
          :node/children opt}
diff --git a/test/dompa/nodes_test.cljc b/test/dompa/nodes_test.cljc
index 53e502a..b1c7b0f 100644
--- a/test/dompa/nodes_test.cljc
+++ b/test/dompa/nodes_test.cljc
@@ -31,6 +31,20 @@
   (is (= "<ul><li>one</li><li>two</li><li>three</li></ul>"
          (list-items ["one" "two" "three"]))))
 
+(defhtml empty-list-items [items]
+  ($ :ul
+     (map (fn [item]
+            ($ :li item))
+          items)))
+
+(deftest empty-list-items-test
+  (testing "map over empty vector should not produce LazySeq string"
+    (is (= "<ul></ul>"
+           (empty-list-items []))))
+  (testing "map over non-empty vector should work"
+    (is (= "<ul><li>one</li><li>two</li></ul>"
+           (empty-list-items ["one" "two"])))))
+
 (deftest $-test
   (testing "a simple node"
     (is (= {:node/name     :div